Teewinot Mountain is one of the great sights of Grand Teton National Park — a soaring 12,325-foot fin of rock that rises straight above Jenny Lake and dominates the view of the range from the valley floor. Its name comes from a Shoshone word meaning “many pinnacles,” and while it can look like a hiking peak from a distance, reaching its summit is a committing mountaineering objective, not a trail walk.

The standard line is the East Face, begun from the Lupine Meadows trailhead south of Jenny Lake. From there the route climbs relentlessly — roughly 4,000 feet of gain in under two miles — first up dozens of steep switchbacks, then through open, flower-filled meadows, and finally onto the face itself. High on the mountain, around 10,500 feet, you pass beneath two prominent rock spires known as the Idol and the Worshipper, a landmark that marks the way onto the upper face.

The climbing is rated roughly 4th class and is often done without a rope by experienced parties, but that grade undersells it: the Tetons are famously sandbagged, the route-finding is complex, exposure is serious, and much of the rock — especially up high — is loose. Snow lingers in the couloirs and the steep “Narrows” well into summer, where an ice axe (and the skill to use it) can be essential. Teewinot is widely considered the deadliest peak in the Tetons: the upper face funnels rockfall, and the crux for many parties is the descent — downclimbing the same steep, loose ground, where many falls and fatalities have occurred. A rope for rappels and downclimbing is wise.

This is a full, dawn-to-dusk day for fit, experienced mountaineers with solid scrambling skills, good judgment, and the gear to match — a helmet is a must for the rockfall, and many climbers hire a guide through the park's concessioners (such as Exum Mountain Guides or Jackson Hole Mountain Guides) for a first ascent. The usual season is mid-summer into early fall, once the snow has consolidated or melted out.

A park entrance fee applies, and this is grizzly country, so carry bear spray on the approach and store food properly. Start in the dark to be off the summit before afternoon thunderstorms build, know the descent as well as the ascent, and turn around if the rock, weather, or your party isn't solid. And if you're not equipped for serious alpine terrain, take heart: Teewinot is arguably even more beautiful from below — admire its pinnacles from the Jenny Lake shore, one of the finest mountain views in the country.

At 13,308 feet in elevation, Gannett Peak is considered to be one of the most difficult state highpoints, rivaled only by Alaska's Denali, Washington's Mount Rainier, and Montana's Granite Peak which have a range of difficulties based on weather and conditions of the climb.

July to August are considered to be the best times to go. If you try too early in the season, all the streams and lakes are still frozen over. If you go too late, then snow and bad weather is more common which makes more a much more strenuous hike. The downside to going in July and August is that the Wind Rivers are renowned for horrendous swarms of voracious mosquitoes. Many climbing parties prefer visiting during July when the Gooseneck Glacier bergschrund (and other crevasses) are not yet fully opened (if at all). Snowpack can actually make a summit attempt less strenuous than travelling on ice and/or rock for long distances.

There are three major trails to the top:

1. Pole Creek Trail to Titcomb Basin
   This is a 40 mile round trip with approximately 9050 feet cumulative elevation gain. This route has long been considered the main standard approach for Gannett Peak, although the Glacier Trail approach from the east has been gaining popularity during recent years. This western approach is a well-travelled route full of spectacular scenery and views.
2. Glacier Trail
   This trail is a 50 mile round trip from the Dubois side and has a cumulative elevation gain of 10,750 feet. The biggest advantage to this route is it puts you at a higher camp for your summit day giving you a better chance of success and less strenuous terrain than the standard western approach.
3. Ink Wells Trail
   The advantage of this route is that a large amount of distance and effort can be saved by the time the route intersects with the Glacier Trail. However, the disadvantage of this route is that access is both limited and expensive. This route crosses the Wind River Indian Reservation, which requires special permission, guidance, and transportation to travel through. Reservations are required in advance and sometimes difficult to achieve, and even if a reservation can be made, the cost can be substantial.